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Topic: rear sprocket (Read 1507 times)

Regarding the rear wheel bearing failure concerns:If it is the same arrangement as the Iron Barrel(which I suspect it is), then it is important to check that the bearing spacer that goes over the axle between the bearings is the right length, and is square.This spacer sets the distance between the inner races, so that the bearing sits in the proper relationship to the distance between the outer races. If this dimension is incorrect, it will force the inner races too far apart, or too far together, and will ruin the bearing in short order. This is very common in Iron Barrel bikes.And the Iron Barrel bikes also use 6203, so I suspect it is all the same layout.Don't assume that all the parts are made properly. Check things yourself.

Aha! I went to my C5 parts catalog, I didn't expect that much detail but it's there.

The wheel bearings are listed as 6005 C3, no mention of seals at all. The sprocket drum bearing is 6203 RS1 C3, single sided seal. The seal is 25x40x7. I'll confirm what I can when I take it all apart soon, though I don't necesarily plan on changing the wheel bearings.

I don't have the G5 catalog with me. I'll check later when I get home.

My G5 parts list says the sprocket uses one (1) RE#145553, which is a 6005 C3 bearing. No mention of seals but if a sealed bearing were used it would work fine.For those with a measuring stick this 6005 bearing has a 25mm (.984") bore, 47mm (1.850") outside diameter and is 12mm (.472) wide.

The wheel hub uses two (2) RE#145552, which is a 6203-RS1-C3 bearings.A measuring stick will show this 6203 bearing has a 25mm (.984") bore, 40mm* (1.5748") outside diameter and is 12mm (.472") wide.

As SinghG5 mentions, it is a good idea to measure what is there before getting a replacement.

Anyone know if it would be a bad idea to just get 2RS bearings sealed on both sides for all three of these bearings? Any reason one or both sides need to be open? Just thinking it would keep more crud out and lengthen their life.

Just wondering about things like extra friction from the seal making them run hotter and whether they need the room for the grease to expand. It would suck to put sealed bearings on only to have them get hot, push out all their grease, then fail.

Just wondering about things like extra friction from the seal making them run hotter and whether they need the room for the grease to expand. It would suck to put sealed bearings on only to have them get hot, push out all their grease, then fail.

Scott

I usually run the shield only on the outer sides, since the inners are sealed from the outside elements. One shield gives less drag on the ball bearings.

Chumma has been using ceramic wheel bearings for the past year, and he really likes them. He says he can feel the difference. They are much more expensive than the steel bearings, and some people say it's a waste of money. We think they work and we have them on several Fireballs now.

Thanks Ace. I doubt I'll give up the extra $$$ for ceramic, I don't think I ride fast or hard enough to justify the cost. Whatever good quality I can get locally will be fine. I could swear the installed bearings are sealed on one side but I'll have to check when I have the wheel off. Good point about not needing two sides sealed since the inners just ride over the spacer anyway.